Changes in cognition as well as other neurologic involvements occur during aging and inorganic dementia of the Alzheimer type. Accompanying changes in the auditory system have not been previously defined. This unique population offers the opportunity to evaluate one twin with the disease and to evaluate the other as his/her control. Pure tone and speech threshold, tests of speech recognition, tests of middle ear function and auditory brain stem functions are being obtained. No data are reportable at this time.